Microcontamination Control in EUV Lithography

This technical note discusses the role of extreme ultraviolet lithography (EUV) in semiconductor technology, specifically focusing on the use of Chemically Amplified Resists (CARs). It outlines the challenges associated with EUV lithography, such as exposure to energetic EUV photons and the presence of molecular contaminants. The document emphasizes the importance of effective filtration in achieving optimal resist performance and reducing defects. A comparative study of various point-of-use (POU) filters is presented, aiming to optimize filtration and improve defectivity in EUV CAR photoresists. The coating process of an EUV CAR is detailed, including the testing procedures for different filters. Results indicate that the R02 filter outperformed others in reducing solvent rinse defects and etched bridge defectivity. The paper concludes by highlighting the critical role of filtration strategies in EUV CARs, emphasizing the need for a thorough understanding of filtration techniques tailored to the challenges of EUV lithography to enhance process reliability.